The Basin Code or "drainage basin code" is a two-digit code that
further subdivides the 8-digit hydrologic-unit code. The
drainage basin code is defined by the USGS State Office where the
site is located.

---------------------------------
CodeDescription
---------------------------------
NAD27 North American Datum of 1927
NAD83 North American Datum of 1983
OLDAK Old Alaska (Mainland) and Aleutian Islands Datum
OLDHI Old Hawaiian
OLDPR Old Puerto Rico and Virgin Islands Datum
OLDSAMOA Old American Samoa Datum
OLDGUAM Old Guam Datum

Y for yes or an N for no to indicate whether the site is in an area
that switches to Local Standard Time (Daylight Savings Time) for a
part of the year.

Site-Type Codes
(site_tp_cd)

A list of primary and secondary site types that can be associated with data collection sites. A site type is a generalized location in the hydrologic cycle, or a man-made feature thought to affect the hydrologic conditions measured at a site. All sites are associated with a primary site type, and may additionally be associated with a secondary site type that further describes the location. The exception to this rule is the Facility primary site type, which must always be associated with a secondary site type. The site type code incorporates these hierarchial distinctions. A list of site type codes is available
[Tab-separated file ||
[Tab-separated --saved to compressed file ||
[Tab-separated --saved to file ||
Table].

State and County FIPS Codes

State code. FIPS state code as defined by FIPS PUB 5-2: Codes for the Identification of the States, the District Of Columbia and the Outlying Areas of the United States, and Associated Areas (http://www.itl.nist.gov/fipspubs/fip5-2.htm).

County FIPS code. A two digit code indicating a U.S. county as defined by FIPS 5-2.

This is a legacy field from the old WATSTORE days therefore the
national consistency of the information/values stored in this field
will vary. This field is actually a 30-POSITION ARRAY of
characters. Coded in one or more locations in the array, will be
the following alpha-code:

---------------------------------
CodeDescription
---------------------------------
A Active data collection site
I Inactive or discontinued data collection site
O Inventory data site only

These codes act as "flags" for the types of data collected in
the following array positions:

---------------------------------
CodeDescription
---------------------------------
e Value has been edited or estimated by USGS personnel and is write protected
& Value was computed from affected unit values
E Value was computed from estimated unit values.
A Approved for publication -- Processing and review completed.
P Provisional data subject to revision.
< The value is known to be less than reported value and is write protected.
> The value is known to be greater than reported value and is write protected.
1 Value is write protected without any remark code to be printed
2 Remark is write protected without any remark code to be printed
No remark (blank)

---------------------------------
CodeDescription
---------------------------------
e The value has been edited or estimated by USGS personnel
A The value is affected by ice at the measurement site.
B The value is affected by backwater at the measurement site.
R The rating is undefined for this value
& This value is affected by unspecified reasons.
K The value is affected by instrument calibration drift.
X The value is erroneous. It will not be used.
< The Value is known to be less than reported value
> The value is known to be greater than reported value
E The value was computed from an estimated value
F The value was modified due to automated filtering.

---------------------------------
CodeDescription
---------------------------------
A Other Gov't Reported by another government agency (do not use "A" if reported by owner, use "O").
D Driller's Log From driller's log or report.
G Geologist Private geologist-consultant or university associate.
L Geophysical Log Depth interpreted from geophysical logs by personnel of source agency.
M Memory Memory (owner, operator, driller).
O Owner Reported by owner of well.
R Other Reported Reported by person other than the owner, driller, or another government agency.
S Reporting Agency Measured by personnel of reporting agency.
U *Unknown Source is unknown.
Z Other Other source (explain in remarks).

---------------------------------
CodeDescription
---------------------------------
e Value has been edited or estimated by USGS personnel and is write protected
& Value was computed from affected unit values
E Value was computed from estimated unit values.
A Approved for publication -- Processing and review completed.
P Provisional data subject to revision.
< The value is known to be less than reported value and is write protected.
> The value is known to be greater than reported value and is write protected.
1 Value is write protected without any remark code to be printed
2 Remark is write protected without any remark code to be printed
No remark (blank)

Flow Adjustment Code (discharge_cd)

The flow adjustment code describes how the sum of the channel discharges was adjusted to get the measurement discharge.

---------------------------------
CodeDescription
---------------------------------
e The value has been edited or estimated by USGS personnel
A The value is affected by ice at the measurement site.
B The value is affected by backwater at the measurement site.
R The rating is undefined for this value
& This value is affected by unspecified reasons.
K The value is affected by instrument calibration drift.
X The value is erroneous. It will not be used.
< The Value is known to be less than reported value
> The value is known to be greater than reported value
E The value was computed from an estimated value
F The value was modified due to automated filtering.

---------------------------------
CodeDescription
---------------------------------
E Excellent The data is within 2% (percent) of the actual flow
G Good The data is within 5% (percent) of the actual flow
F Fair The data is within 8% (percent) of the actual flow
P Poor The data are >8% (percent) of the actual flow

The rating control condition code describes the condition of the rating control
at the time of the measurement. The possible values for the code are:

----------------------------------------------------------------
CodeDescription
----------------------------------------------------------------
UNSP The stream control conditions were not specified.
AICE The stream control is covered with anchor ice.
CICE The stream control was convered by ice.
CLER The stream control was clear of any obstructions.
FILL The stream control was filled.
HVDB The stream control was heavily covered with debris.
LGDB The stream control was lightly covered with debris.
ALGA The stream control was covered with moss/algae.
MAHV The stream control was heavily covered with moss/algae.
MALT The stream control was lightly covered with moss/algae.
MAMD The stream control was moderately covered with moss/algae.
MDDB The stream control was moderately covered with debris.
NFLW There was no flow over the stream control.
SCUR The stream control has scour conditions.
SICE The stream control has shore ice.
SUBM The stream control was submerged.

Statistic Codes (stat_cd)

Statistic code. The statistic code of all the unit values for the DD. Most common is 00011 (instantaneous), but some recorders sample the stream on some very frequent interval and report things like the minimums, maximums, and means of all the samples taken for a longer interval. So, for example, the recorder would output a set of values every 15 minutes that are the min., max., and mean of the values taken every 30 seconds during those 15 monites. Data from recorders like those would use a statistic code such as 00001 (max), 00002 (min), or 00003 (mean) in the DD. The possible values are:
[Tab-separated file ||
[Tab-separated --saved to compressed file ||
[Tab-separated --saved to file ||
Table].

Streamflow Method (streamflow_method)

The streamflow method describes the method used to measure the discharge.

Fixed Value Parameter Codes (fxd)

Hydrologic Condition Codes (hyd_cond_cd)

The hydrologic condition code is a single alphanumeric character that identifies the height and change of the river or aquifer during a sampling. The codes and descriptions are: "A" Not determined, "4" Stable, low stage, "5" Falling stage, "6" Stable, high stage, "7" Peak stage, "8" Rising stage, and "9" Stable, normal stage.

Hydrologic Event Code (hyd_event_cd)

The hydrologic event code is a single alphanumeric character that identifies a weather event or other environmental event which may affect the quantity or quality of water in a river or aquifer during sampling.

Medium codes, descriptions, and definitions (medium_cd)

The medium code is the 3-character alpha code that identifies the material type and quality-assurance type of the sample. The first character of the code is the "super" medium, which describes the primary matrix of the sample. The second character is the sub-medium, which characterizes the sample type as a unique entity within the "super" medium category. The third character is used to designate whether a sample is an environmental or QC sample. A blank in position three denotes an environmental sample; a "Q" in position three denotes a QC sample.

Sample Type Codes (samp_type_cd) identify the QA type of a sample.

Taxonomic Unit (tu)

Legal taxon name and associated attributes for levels of taxonomic hierarchy structure from kingdom to genus. Genus, binomials/polynomials are identified.

Time Datum Reliability Codes (tm_datum_rlblty_cd)

The time datum reliability code is used to describe how well the time datum is known. For times entered prior to NWIS 4.3, there is no reliable means of determining the reliability, so the code is set to 'T'. For times entered after NWIS 4.3, the reliability should be known or estimated.

Value Qualifier Codes (val_qual_cd)

Value qualifier code. Value qualifiers identify specific exceptional or unusual characteristics of the measurement process used to determine a result. Value qualifiers provide additional information about the causes and possible direction of bias, and/or the magnitude of variability for the measurement.